The inhabitants of cold climates require those articles of food
which produce the largest amount of animal heat, such as oil,
tallow and fat meats, which contain from sixty-six to eighty per
cent. of carbon. The natives of the arctic regions consume enormous
quantities of fat and oil, and seem to relish them as great luxuries;
the inhabitants of tropical regions subsist mainly on rice, fruits,
vegetables and lean meats. It would be impossible to live in
Greenland on the plaintain and rice of the Hindoo, or in Hindostan on
the seal fat and whale oil of the Greenlander.
In temperate climates we require different kinds of food at different
seasons of the year. In winter we consume larger quantities of fat
meat and carbonaceous food, and in summer more fruit and vegetables.
Were we to indulge in the summer in the same diet which we might
find highly conducive to health in the winter, the system would
soon become burdened with an excess of carbonaceous matter, and
induce congestion and inflammatory diseases. It is therefore highly
important that each person should possess some knowledge of the
properties of different articles of diet, and select from time to
time those which he may think most suitable to his own organization.
Different substances are nutritious in proportion as they yield, when
digested, those elements which are found to exist in the different
tissues of the body. Animals do not possess the power of forming
new elements, or of converting one element into another, and it
necessarily follows that the elements of their growth and nutrition
must be derived from the food which they take.
The largest part of nearly all the substances which make up the human
body are composed of oxygen, hydrogen, nitrogen and carbon, and
different substances are regarded as nutritious in proportion as they
furnish these essential elements of our organization. In general,
those substances may be regarded as the most important articles of
diet which furnish, with the greatest facility of digestion, the
largest amount of these elements.
Milk is regarded, perhaps correctly, as the plainest and simplest
kind of food. Cow’s milk is composed of:
Casein, 4.48
Butter, 3.13
Sugar of milk, 4.77
Various salts, .60
Water, 87.00
Milk, being furnished by nature as the only food for the young of the
mammalia during a certain period of their existence, contains all the
elements necessary to the nutrition and the growth of the body. Out
of the casein are formed the albumen and fibrin of the blood. The
butter serves for the formation of fat, and contributes, with the
sugar, to the support of animal heat, by yielding carbon and hydrogen
to be burnt in the lungs. The earthy salts (phosphate of lime, etc.)
are necessary for the development of the bones, the iron required for
the blood, corpuscles and the hair.
In this country, meat constitutes an important part of the diet of
almost every family. As a general rule, animal food is more easily
digested, contains a greater amount of nutriment, and is more
stimulating than any of the varieties of vegetable food.
As minuteness of division and tenderness of fibre facilitate
digestion, young meats are more tender than old; thus, roasted pig
is more speedily digested than broiled pork; steak and boiled lamb
sooner than boiled mutton. Still, there are some exceptions to the
digestibility of young meats, veal, and with some persons lamb, are
slower of digestion than beef or mutton.
The vegetable kingdom greatly exceeds the animal in the number and
variety of the aliments which it furnishes to man. It is well known
that the four essential elements, carbon, oxygen, hydrogen and
nitrogen, which form an important part of all animal compounds, are
also to be found in great abundance in all vegetable compounds; it is
owing to this fact that different animals are nourished equally well
on an exclusive diet of either. The lion, tiger and other animals
which live exclusively on animal food, give no evidence of being
better nourished than the deer, the ox, and animals which subsist
wholly on vegetable food; but the apparatus for digestion in each
class is constructed with an evident adaptation to the kind of diet
on which the different animals subsist.
In man the digestive apparatus is more extensive than in flesh-eating
animals, but is less complicated than in those which are confined
to vegetable food alone. Man is therefore omnivorous, both in his
structure and in his habits.
But the universal tendency of mankind gives preference to a mixed
diet. The most perfect development and the greatest individual vigor
are to be found among those races in which a mixed diet is the
prevalent habit.
During the warm season vegetables and fruits may be made the means of
great mischief or of great good. Perfectly ripe fruits or vegetables
are highly useful and well adapted to the wants of the system at that
season of the year; yet they may become, and often are, a prolific
source of disease. So frequently is this kind of food a cause of
bowel complaint that city physicians discard it wholly from the diet
of children not under their immediate supervision.
Vegetables and early fruits that have been long exposed, in a
malarious or filthy market, or in transportation, are unquestionably
dangerous articles of food for all persons. But the injurious
consequences which follow the use of ripe and wholesome vegetables
and fruit are, in almost all cases, the results of imprudence. They
are either in an improper condition to be used as food, or the
quantity is too great, or they are taken at improper hours.
In either case there is a great change in the usual diet. Instead
of a lack of refrigerant food, there is now an excess of it. Active
fermentation takes place in the process of digestion, and results in
serious derangement in the alimentary canal, which leads to cholera
morbus, diarrhœa or dysentery.
During warm weather vegetables and fruit are to be regarded as safe
only when used as an accompaniment to other food; they are not
adapted to meet all the wants of the system, and therefore should not
constitute a full meal at any time. In the country, where this kind
of food is enjoyed daily in a proper condition to be eaten, injurious
consequences are quite rare, and then they are the result of an
excess, or of an indulgence of an appetite at irregular hours.
Much care is also requisite to prevent imperfect mastication of this
kind of food. Orange peel and the skins and stones of cherries, plums
and grapes are wholly indigestible, and often cause serious mischief
when swallowed. Cucumbers, green potatoes, green fruit of all kinds
should be wholly discarded from the diet.